Eosimias sinensis (Chinese: 中华曙猿, "dawn monkey of China") was a primate species of Eosimias first discovered in China. It was first discovered in a mountain near Liyang City, Jiangsu province, China. It is the earliest catarrhine that has been discovered.
The species is believed to have lived 45 million years before present, in the Eocene epoch. E. sinensis was tiny, as small as the smallest monkey presently, the Pygmy Marmoset (Cebuella pygmaea) of South America, and could fit in the palm of a human's hand. Its teeth are considered more primitive than those of early higher primates known from Africa, including Algeripithecus minutus. Due to its highly primitive nature, some paleontologists consider E. sinensis to be evidence that higher primates may have originated in Asia rather than Africa.